Muscular System Functions and Types

Muscular System

• Functions:
  • Movement
  • Support
  • Stability
  • Regulation of body temperature
• Types of muscle tissue:
  • Skeletal muscle (voluntary)
  • Smooth muscle (involuntary)
  • Cardiac muscle (involuntary)
• Characteristics of skeletal muscle:
  • Striated (striped) appearance
  • Multinucleated
  • Voluntary control
• Characteristics of smooth muscle:
  • Non-striated appearance
  • Single nucleus
  • Involuntary control
• Characteristics of cardiac muscle:
  • Striated appearance
  • Single nucleus
  • Involuntary control

Skeletal System

• Functions:
  • Support
  • Protection
  • Movement
  • Blood cell production
• Types of bones:
  • Long bones (e.g. femur, humerus)
  • Short bones (e.g. carpals, tarsals)
  • Flat bones (e.g. ribs, sternum)
  • Irregular bones (e.g. vertebrae, pelvis)
• Bone structure:
  • Compact bone (dense, outer layer)
  • Cancellous bone (spongy, inner layer)
• Joints:
  • Types: synovial, cartilaginous, fibrous
  • Examples: shoulder, elbow, knee, hip

Nervous System

• Functions:
  • Control and coordination
  • Sensation and perception
  • Regulation of body functions
• Divisions:
  • Central Nervous System (CNS): brain, spinal cord
  • Peripheral Nervous System (PNS): nerves, ganglia
• Neurons:
  • Structure: dendrites, cell body, axon
  • Function: transmission of nerve impulses
• Types of neurons:
  • Sensory neurons
  • Motor neurons
  • Interneurons
• Glial cells:
  • Types: astrocytes, oligodendrocytes, microglia
  • Functions: support, protection, maintenance

Circulatory System

• Functions:
  • Oxygen delivery
  • Carbon dioxide removal
  • Nutrient delivery
  • Waste removal
• Components:
  • Heart
  • Arteries
  • Veins
  • Blood vessels
• Blood:
  • Composition: plasma, red blood cells, white blood cells, platelets
  • Functions: oxygen transport, immune function, clotting
• Blood pressure regulation:
  • Baroreceptors
  • Renin-angiotensin-aldosterone system

Muscular System

• The muscular system provides movement, support, stability, and regulates body temperature
• There are three types of muscle tissue: skeletal, smooth, and cardiac muscle
• Skeletal muscle is voluntary, striated, and multinucleated, and allows for movement and locomotion
• Smooth muscle is involuntary, non-striated, and single-nucleated, and is found in the walls of hollow organs and blood vessels
• Cardiac muscle is involuntary, striated, and single-nucleated, and is responsible for the heartbeat

Skeletal System

• The skeletal system provides support, protection, movement, and produces blood cells
• There are four types of bones: long, short, flat, and irregular bones
• Long bones, such as the femur and humerus, are characterized by their length and are found in the limbs
• Short bones, such as the carpals and tarsals, are Cube-shaped and are found in the wrists and ankles
• Flat bones, such as the ribs and sternum, are thin and curved and provide protection for internal organs
• Irregular bones, such as the vertebrae and pelvis, do not fit into any other category and provide support and protection for the body
• Bones are composed of compact and cancellous bone tissue, with compact bone forming the dense outer layer and cancellous bone forming the spongy inner layer
• Joints allow for movement and are classified into three types: synovial, cartilaginous, and fibrous

Nervous System

• The nervous system provides control and coordination, sensation and perception, and regulates body functions
• The nervous system is divided into the central nervous system (CNS) and peripheral nervous system (PNS)
• The CNS consists of the brain and spinal cord, and integrates and processes information
• The PNS consists of nerves and ganglia, and transmits information to and from the CNS
• Neurons are the basic functional units of the nervous system, and transmit nerve impulses
• Neurons have three main components: dendrites, cell body, and axon
• There are three types of neurons: sensory, motor, and interneurons
• Glial cells provide support, protection, and maintenance for neurons, and are classified into three types: astrocytes, oligodendrocytes, and microglia

Circulatory System

• The circulatory system delivers oxygen, removes carbon dioxide, and transports nutrients and waste
• The circulatory system consists of the heart, arteries, veins, and blood vessels
• Blood is composed of plasma, red blood cells, white blood cells, and platelets, and provides oxygen transport, immune function, and clotting
• Blood pressure is regulated by baroreceptors and the renin-angiotensin-aldosterone system, which helps to maintain blood pressure and blood volume

Pelvis

• Bony structure consists of four fused bones: ilium, ischium, and pubis
• Sacrum and coccyx form the posterior aspect of the pelvis
• Pelvic girdle is formed by the ilium, ischium, and pubis
• Acetabulum is the socket for the femoral head
• Greater sciatic notch is the passage for the piriformis muscle
• Lesser sciatic notch is the passage for the tendon of the obturator internus

Muscles of the Pelvis

• Pelvic floor muscles include levator ani, coccygeus, and iliococcygeus
• Gluteal muscles include gluteus maximus, gluteus medius, and gluteus minimus

Lower Limb

Hip Joint

• Type of joint: ball-and-socket
• Bony structure consists of the femoral head (proximal end of femur) and acetabulum (pelvis)
• Iliofemoral ligament strengthens the joint anteriorly
• Pubofemoral ligament strengthens the joint anteromedially
• Ischiofemoral ligament strengthens the joint posteromedially

Thigh

• Bony structure consists of the femur, the longest bone in the body
• Anterior compartment muscles include quadriceps femoris (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius)
• Posterior compartment muscles include hamstrings (biceps femoris, semitendinosus, and semimembranosus)
• Medial compartment muscles include adductor magnus, adductor longus, and adductor brevis

Knee Joint

• Type of joint: hinge joint
• Bony structure consists of the distal end of femur and proximal end of tibia
• Anterior cruciate ligament (ACL) prevents anterior translation of the tibia
• Posterior cruciate ligament (PCL) prevents posterior translation of the tibia
• Medial collateral ligament (MCL) prevents medial rotation of the tibia
• Lateral collateral ligament (LCL) prevents lateral rotation of the tibia

Leg

• Bony structure consists of tibia (medial bone) and fibula (lateral bone)
• Anterior compartment muscles include tibialis anterior, extensor hallucis longus, and extensor digitorum longus
• Lateral compartment muscles include peroneus longus and peroneus brevis
• Posterior compartment muscles include gastrocnemius, soleus, and plantaris

Ankle and Foot

• Bony structure consists of talus, calcaneus, cuboid, navicular, cuneiform bones, metatarsals, and phalanges
• Dorsiflexors include tibialis anterior, extensor hallucis longus, and extensor digitorum longus
• Plantarflexors include gastrocnemius, soleus, and plantaris